Nether portals teleporting player in the wrong position (Overworld to Nether, keeps overworld co-ordinates)

My friend was hosting a survival world, he entered the nether and was teleported to the wrong position. No nether portal was present where he was (Over 1000 blocks from the correct position). I entered the nether and appeared in the correct position. This bug is inconsistent. We were using the "Enable Gametest Framework" option when in the world.